This invention relates to a working cylinder having a working chamber defined by a cylinder barrel, at least one of the end sections and a piston, at least one supply port for the working medium for this working chamber, an exhaust port for the working medium from this working chamber, a valve, specifically for controlling this type of working cylinder; at least one inlet and one outlet for a work medium; at least one control port or a switch valve, specifically for controlling a double-action working cylinder; at least one connector and at least two outlets for a working medium; at least one control port; a working unit, including at least one compression source for the working medium; at least one and at the most a double-action working cylinder; at least one valve for controllable supply of the working cylinder with a working medium; and at least one line for the working medium from the valve to the working cylinder.
Multiple functions are necessary for the conversion of pneumatic energy to mechanical power, for example, whereby these functions are performed by various components, elements or group of components of the pneumatic working units in this case. Thereby the signal to move forward is converted into an air pressure signal of the corresponding working chamber in the working cylinder and possibly convert it to a depressurizing signal of the opposed chamber or these signals are to be combined. This is accomplished in traditional designs by a valve, which also takes care of conversion of the compressed air network in the corresponding working chamber, opening of the opposed chamber to depressurize the cylinder, and discharge of the outgoing air into the atmosphere. The line as well as the compressed air network to the cylinder are pneumatic lines, which only take care of the conversion of air pressure to mechanical power through the cylinder piston and the discharge of air from the cylinder into the atmosphere. Up to now, pneumatic cylinders were pressurized and depressurized through the same lines even though these two functions required different diameters. Valves use up to now for the control of double-action pneumatic cylinders had to be designed large in size because their function and the diversion of the pressure medium into the corresponding cylinder chamber and also because of the depressurization control of each opposed chamber whereby a large amount of space remained unused at the end sections of the pneumatic cylinders. The situation was similar for hydraulic units.
The object of the present invention is therefore to create elements for a pressure-actuated working unit and to create an improved working unit of this type in itself, whereby a smaller size in design of at least the valve is obtained, the already existing space in the cylinder is better utilized and the output capacity of the individual elements is adjusted better and more efficiently.
This object is reached primarily with a working cylinder of the above-mentioned type, according to the invention, in that the cylinder exhaust port has a valve, which may be regulated by the pressure of the working medium at the supply port. Thereby, for example, a component group for a function of the pressure-actuated pneumatic working unit is moved from the valve into the working cylinder, preferably into its end section, where there is already sufficient space for the corresponding component without the need for larger dimensions. Therefore, the valve itself may be made smaller because of the elimination of components necessary for discharge or depressurization control.
Further improved space utilization is accomplished, according to an advantageous embodiment, in that the supply port and the exhaust port are directly connected to one another by a passageway for the working medium, whereby the valve is installed inside this passageway.
Optimal space utilization within the working cylinder is possible if a supply channel to the work area leads from the supply port for the working medium, parallel to the passageway, and subsequently to the exhaust port.
In order to satisfy the different requirements for pressurizing and depressurizing or for supplying and discharging of the working medium, it is advantageously planned that the supply channel has a smaller diameter than the passageway to the exhaust port. Now the pressurizing or supplying of the working medium may be accomplished in a simple way without additional structural efforts by better using the smaller diameter channel and by using the optimal larger diameter channel for depressurizing the working cylinder or for discharging the working medium.
Requirements may be solved in an advantageous manner and in a simple design concerning noise protection in case of pneumatic systems or concerning the flow phenomenon in case of hydraulic systems, by topping the exhaust port with a speed throttle element and/or a muffler.
According to an advantageous embodiment of the invention, the valve has in its design a sealing element that moves freely and covers the passageway and which also covers the supply channel at least partly.
Thereby there has been realized, in a simple and very functional manner, the above-mentioned control for depressurizing dependent on pressurizing or discharge of the working medium dependent on applying pressure to the working chamber of the cylinder.
The innovative construction of the working cylinder is especially advantageous if it is designed as a double-action cylinder and if it is preferably made at each side as shown in the above-mentioned paragraph and by being the same at both sides, at least functionally, thereby the mentioned advantages are twice as much, meaning advantages for both sides are taken into consideration.
The first-mentioned valve, which is particularly meant to be used for the control of the innovative pneumatic working cylinder, is identified according to an additional characteristic of the invention by an exhaust channel for the working medium, originating from a location between the throttle element of the valve and at least one outlet, whereby there is located an adjustable discharge or depressurizing valve within this exhaust channel, which may be adjusted by the pressure that is applied at the control port. This channel may be placed within the valve housing itself or in one of the elements within the valve and this causes thereby no increase in its dimensions. The valve must therefore be only large enough to contain the absolutely necessary connections and control elements so that optimal functioning is reached with the smallest structural dimension.
As firstly described, there is a switch valve designed for the double-action working cylinder, characterized by at least one exhaust channel for each cylinder located between the valve element and each outlet, whereby there is located in each exhaust channel at least one adjustable discharge or exhaust control valve that has pressure applied at the control port. Thereby, the same advantages have been reached as mentioned for the previous arrangement, whereby the air net connection or the connection for the source of the pressure medium must be connected alternately to one of the two working cylinders. The same is true, in principle, for an electric adjustable discharge or exhaust valve.
According to an especially advantageous embodiment, there is a switch valve designed as a rocker valve, which has a switchable rocker seal element between two switching positions that has pressure applied to the control connection so that the discharge or exhaust control valve remains in an effective connection with the control area through at least one device for transferring the pressure that is applied to the control port. With this type of design there is guaranteed an immediate safe and rapid depressurizing control or control for exhaust of the pressure medium from the working cylinder by having the smallest wasted space, allowing rapid switching even with large port diameters, and keeping a tight seal. Based on the small pivoting movement of the rocker, which is sufficient for the switching action, the innovative valve may be built in a very small and flat shape and may be built in layered sections that allow easy operating, easy repair and assembly. With the innovative design of the switch valve, a smaller size in construction has been reached as compared even with two rocker valves for a 5/2-way function.
A flexible membrane is advantageously planned that is a part of the wall in the control area and which serves as a device for transferring pressure to actuate the actual sealing element through a valve shaft. This sealing element thereby blocks or opens the discharge channel. This ensures a very good switching capability of the discharge or exhaust valve in a structural simple and space-saving manner.
As a matter of course, the above mentioned advantages may be doubled by optimal utilization of the existing spaces, which applies to both sides for which control is necessary and where the switch valve has at least the same functional design at both sides.
The innovative pneumatic working unit includes at least one pressure source for the working medium, at least one pneumatic working cylinder, at least one valve for the controllable supply of the working cylinder with a working medium, at least one line for the working medium from the valve to the working cylinder. It is characterized by better space utilization and downsizing or decreasing of components as well as better power adjustment of the elements. It is also characterized in that there is only one line to the cylinder per cylinder working chamber carrying the working medium, the lines may be depressurized or the pressure may be reduced by the use of at least one switchable discharge or exhaust valve, the working cylinder is designed according to at least one of the above-mentioned paragraphs and whereby its exhaust port is kept open.
It is planned, for example, that pressure be applied to the control port of the discharge or exhaust valve to reach the best possible and structural most simple combination of pressurizing and depressurizing function or supplying and discharging of the working medium.
In a preferred way, and to reach the above-mentioned advantages, the working unit is characterized by a valve arrangement which has a exhaust channel for the working medium that originates at a location between the shut-off element of the valve and at least one outlet and whereby there is located in this exhaust channel a discharge or exhaust valve that is controlled by the pressure applied at the control port.
The pneumatic working unit, which has at least one double-action pneumatic working cylinder, is characterized according to one advantageous version in that there is one line per working cylinder carrying the working medium, that the working cylinder corresponds to at least one of the related paragraphs, and that one switch-valve arrangement corresponds to at least one of the above related paragraphs.
According to an additional invention characteristic, there is a control logic arrangement, which has connectors for communication (preferably a field bus), electrical control and supply for the working medium. Thereby a more compact size of the working unit is possible even at increased versatility.
According to another characteristic of the invention, the valve to control one or both working chambers of the working cylinder may of course be directly attached to it or integrated within, preferably in one of the end sections of the cylinder.
One or each exhaust control valve may also be advantageously attached to the working cylinder or the switch valve or may be structural integrated within. In both cases, there is far reaching simplification in assembly and arrangement at the assembly point. Furthermore, lines may be eliminated between these assembled components and in case of structural integration, connections and sealing areas may also be eliminated, whereby, on the one hand, the arrangement of the entire system is greatly simplified and, on the other hand, its operational dependability may be increased considerably based on less danger of leakage. The just-mentioned possibilities may also be applied advantageously in the design of the switch valve in its rocker type construction.
Some design examples of pneumatic versions are explained in more detail in the subsequent description as they relate to the attached drawings, whereby these examples are not to be evaluated in any way as limitations to the general innovative idea encompassed by the accompanying claims.